Driving circuit of thin membrane EL display apparatus

Claim 2

A driving circuit for an electroluminescent (EL) matrix display panel wherein an EL layer is disposed between orthogonally arranged scanning electrodes and the data electrodes, comprising: a first switching circuit for selectively applying negative or positive-polarity driver output voltages to the scanning electrodes; a second switching circuit for supplying charging and discharging modulation driver output voltages to the data electrodes; said first and second switching circuits each including a plurality of first, second high withstand-voltage drivers having push/pull functions, said drivers including a high level drive voltage input, a low level drive voltage input, a single control voltage input, each said driver selecting one of said drive voltage inputs for supply as said driver output voltage; a third switching circuit for switching between a negative polarity writing voltage and 0V and connected with the low level drive voltage input of each said driver of said first switching circuit for pull down use of the first high withstand-voltage driver in the first switching circuit; a fourth switching circuit for switching between a positive-polarity of writing voltage and 0V and connected with the high level drive voltage input of each said driver of said first switching circuit for pull up use; the low level drive voltage input of each said driver of said second switching circuit being for pull down use and being connected with 0V; and a fifth switching circuit for switching the high level drive voltage input of said second switching circuit between a floating, level and into the modulation voltage V M .

Claim 3

A driving circuit for an electroluminescent (EL) matrix display panel wherein an EL layer is disposed between orthogonally arranged scanning electrodes and data electrodes, comprising: a first switching circuit for selectively applying negative or positive-polarity driver output voltages to the scanning electrodes; a second switching circuit for supplying charging and is charging modulation driver output voltages to the data electrodes; said first and second switching circuits each including a plurality of high withstand-voltage drivers having push pull functions, said drivers including a high level drive voltage input, a low level drive voltage input, a single control voltage input, each said driver selecting one of said drive voltage inputs for supply as said driver IC output voltage; a third switching circuit for switching between the negative polarity of writing voltage, the 1/2 modulation voltage and 0V and connected with the low level drive voltage input of each said driver of said first switching circuit for pull down use of the high withstand-voltage driver in the first switching circuit; a fourth switching circuit for switching between a sum of a positive polarity of writing voltage and the 1/2 modulation voltage, and the 1/2 modulation voltage and connected with the high level drive voltage input of each said driver of said first switching circuit for pull up use, the low level drive voltage input of each said driver of said second switching circuit being for pull down use and being connected with 0V; a fifth switching circuit for switching the high level drive voltage input of said second switching circuit between a floating level and the 1/2 modulation voltage; and a sixth switching circuit for doubling a 1/4 modulation voltage to develop the 1/2 modulation voltage for supply to the third, fourth, fifth switching circuits.

Claim 4

A driving circuit for an electroluminescent (EL) matrix display panel wherein an EL layer is disposed between orthogonally arranged scanning electrodes and data electrodes, comprising: a first switching circuit for selectively applying negative or positive-polarity driver output voltages to the scanning electrodes; a second switching circuit for supplying charging and is charging modulation driver output voltages to the data electrodes; said first and second switching circuits each including a plurality of high withstand-voltage drivers having push pull functions, said drivers including a high level drive voltage input, a low level drive voltage input, a single control voltage input, each said driver selecting one of said drive voltage inputs for supply as said driver IC output voltage; a third switching circuit for switching between the negative polarity of writing voltage, the 1/2 modulation voltage and 0V and connected with the low level drive voltage input of each said driver of said first switching circuit for pull down use of the high withstand-voltage driver in the first switching circuit; a fourth switching circuit for switching between a sum of a positive polarity of writing voltage and the 1/2 modulation voltage, and the 1/2 modulation voltage and connected with the high level drive voltage input of each said driver of said first switching circuit for pull up use, the low level drive voltage input of each said driver of said second switching circuit being for pull down use and being connected with 0V; a fifth switching circuit for switching the high level drive voltage input of said second switching circuit between a floating level and the 1/2 modulation voltage; and a sixth switching circuit for doubling a 1/4 modulation voltage to develop the 1/2 modulation voltage for supply to the third, fourth, fifth switching circuits.

Claim 5

The driving circuit of claim 1 or 2, comprising, a bidirectional switch connected to one of said drive voltage inputs of at least some of said drivers for externally recovering, after the light-emission of the EL display, electric charge accumulated upon the EL display, and a capacitor for accumulating the recovered electric charge for later use in again driving the display.

Claim 6

A drive system for an electroluminescent (EL) matrix display panel including a plurality of scanning electrodes and a plurality of data electrodes extending orthogonally of each other across respective sides of an electroluminescent material, said scanning electrodes and said data electrodes forming picture elements at each intersection therebetween, said scanning electrodes arranged into odd and even groups, said drive system comprising: scanning drive means arranged for connection with said scanning electrodes for sequentially supplying said scanning electrodes with write voltage pulses, said scanning drive means driving said odd and even scanning electrodes in first and second fields, said odd scanning electrodes being driven with a positive write voltage during the first field and a negative write voltage during the second field, said even scanning electrodes being driven with a negative write voltage during the first field and the positive write voltage during the second field; data drive means arranged for connection with said data electrodes for selectively charging or discharging each said data electrode with a modulation voltage to selectively develop a net voltage between a said scanning electrode supplied a write voltage and each said selected data side electrode to selectively color the picture elements formed at the intersections thereof; said scanning drive means including a pull up-pull down circuit associated with each said scanning electrode, said pull up-pull down circuit supplying one of two drive voltages supplied to said circuit to its associated scanning electrode in response to a single voltage input.

Claim 7

A drive system for an electroluminescent (EL) matrix display panel including a plurality of scanning electrodes and a plurality of data electrodes extending orthogonally of each other across respective sides of an electroluminescent material, said scanning electrodes and said data electrodes forming picture elements at each intersection therebetween, said scanning electrodes arranged into odd and even groups, said drive system comprising: scanning drive means arranged for connection with said scanning electrodes for sequentially supplying said scanning electrodes with write voltage pulses, said scanning drive means driving said odd and even scanning electrodes in first and second fields, said odd scanning electrodes being driven with a positive write voltage during the first field and a negative write voltage during the second field, said even scanning electrodes being driven with a negative write voltage during the first field and the positive write voltage during the second field; data drive means arranged for connection with said data electrodes for selectively charging or discharging each said data electrode with a modulation voltage to selectively develop a net voltage between a said scanning electrode supplied a write voltage and each said selected data side electrode to selectively color the picture elements formed at the intersections thereof; said scanning drive means including a pull up-pull down circuit associated with each said scanning electrode, said pull up-pull down circuit supplying one of two drive voltages supplied to said circuit to its associated scanning electrode in response to a single voltage input.

Claim 8

The system of claim 4 wherein said data drive means includes a pull up-pull down circuit associated with each said data electrode, said pull up-pull down circuit supplying one of two drive voltages supplied to said circuit to its associated data electrode in response to a single voltage input.

Claim 9

The system of claim 4 wherein each said pull up-pull down circuit includes, a high level drive voltage input, a low level drive voltage input, a single control voltage input, a bidirectional switching element responsive to said single control voltage input for supplying one of said two drive voltages to an output thereof.

Claim 10

The system of claim 5 wherein each said pull up-pull down circuit includes, a high level drive voltage input, a low level drive voltage input, a single control voltage input, a bidirectional switching element responsive to said single control voltage input for supplying one of said two drive voltages to an output thereof.

Claim 11

A drive system for an electroluminescent (EL) matrix display panel including a plurality of scanning electrodes and a plurality of data electrodes extending orthogonally of each other across respective sides of an electroluminescent material, said scanning electrodes and said data electrodes forming picture elements at each intersection therebetween, said scanning electrodes arranged into odd and even groups, said drive system comprising: scanning drive means arranged for connection with said scanning electrodes for sequentially supplying said scanning electrodes with write voltage pulses, said scanning drive means driving said odd and even scanning electrodes in first and second fields, said odd scanning electrodes being driven with a positive write voltage during the first field and a negative write voltage during the second field, said even scanning electrodes being driven with a negative write voltage during the first field and the positive write voltage during the second field; data drive means arranged for connection with said data electrodes for selectively charging or discharging each said data electrode with a modulation voltage to selectively develop a net voltage between a said scanning electrode supplied a write voltage and each said selected data side electrode to selectively color the picture elements formed at the intersections thereof; charge storage device means, external of said matrix display panel for temporarily storing charge discharged from said display panel; and bidirectional switch means of selectively connecting said charge storage device means to said scanning electrode drive means or said data electrode drive means to direct charge to said charge storage device means during discharge of at least portions of said display panel and to direct charge to at least portions of said display panel when the charge stored in said charge storage means can be used to drive a portion of said display.

Claim 12

A drive system for an electroluminescent (EL) matrix display panel including a plurality of scanning electrodes and a plurality of data electrodes extending orthogonally of each other across respective sides of an electroluminescent material, said scanning electrodes and said data electrodes forming picture elements at each intersection therebetween, said scanning electrodes arranged into odd and even groups, said drive system comprising: scanning drive means arranged for connection with said scanning electrodes for sequentially supplying said scanning electrodes with write voltage pulses, said scanning drive means driving said odd and even scanning electrodes in first and second fields, said odd scanning electrodes being driven with a positive write voltage during the first field and a negative write voltage during the second field, said even scanning electrodes being driven with a negative write voltage during the first field and the positive write voltage during the second field; data drive means arranged for connection with said data electrodes for selectively charging or discharging each said data electrode with a modulation voltage to selectively develop a net voltage between a said scanning electrode supplied a write voltage and each said selected data side electrode to selectively color the picture elements formed at the intersections thereof; charge storage device means, external of said matrix display panel for temporarily storing charge discharged from said display panel; and bidirectional switch means of selectively connecting said charge storage device means to said scanning electrode drive means or said data electrode drive means to direct charge to said charge storage device means during discharge of at least portions of said display panel and to direct charge to at least portions of said display panel when the charge stored in said charge storage means can be used to drive a portion of said display.

Claim 13

The drive system of claim 4 wherein said modulation voltage is applied to a said data electrode associated with a picture element simultaneous to the application of a said write voltage pulse to said picture element.

Claim 14

The drive system of claim 4 wherein said data drive means includes, a pair of serially connected switches, associated with each said data electrode, connected between a high level drive voltage input and a low level drive voltage input, said associated data electrode being connected between said switches, and first and second diodes, associated with each said data electrode, each connected across one of said pair of switches and being conductive in the direction opposite normal switch conduction.

Claim 15

The drive system of claim 10 wherein said data drive means further includes, a shift register serially receiving data to be displayed; and inverter means, connected between each stage of said shift register and a control terminal of each said switch to control the conduction of one switch of each switch pair to selectively supply said high level drive voltage input or low level drive voltage input to the associated data electrode.

Claim 16

The drive system of claim 11 wherein said data drive means further includes, frame switching means for supplying said modulated voltage to said data electrode during the first field and for grounding said data electrode during the second field to develop a display at a selected picture element on said data side electrode.

Claim 17

The drive system of claim 12 wherein said frame switching means comprises an exclusive OR gate inverting said data in alternate frames.

Claim 18

The drive system of claim 4 wherein each said pull up-pull down circuit of said scanning drive means includes, a pair of serially connected switches, associated with each said scanning electrode, connected between a high level drive voltage input and a low level drive voltage input, said associated scanning electrode being connected between said switches, and first and second diodes, associated with each said scanning electrode, each connected across one of said pair of switches and being conductive in the direction opposite normal switch conduction.

Claim 19

The drive system of claim 10 wherein said scanning drive means further includes, a shift register serially receiving scanning to be displayed; and inverter means, connected between each stage of said shift register and a control terminal of each said switch to control the conduction of one switch of each switch pair to selectively supply said high level drive voltage input or low level drive voltage input to the associated scanning electrode.

Claim 20

The driving circuit of claim 1 or 2 wherein each said high withstand-voltage driver is controlled by an output of a single shift register.

Claim 21

The driving system of claim 4 wherein said single voltage input of the pull up-pull down circuit associated with each said scanning electrode is developed by an output of a single shift register, said single voltage input of the pull up-pull down circuit associated with each even scanning electrode being developed by an output of a single shift register.